Telephone system



March26, 1946. a. BABCOCK TELEPHONE SYSTEM Filed July 27, 1942- INVENTOR Gar/26022 Eabcook,

um a mm Patented Mar. 26, 1946 UNITED STATES PATENT OFFICE TELEPHONE SYSTEM. Garrison Babcock, Seattle, Wash. :7 Application July 27,, 1942, Serial No. 452,987. 9 19 Claims, (01; 179-71) This invention relates to telephone systems, and more particularly to telephone system employing means for giving metered service.

One of the main objects of the present invention is to provide means for registering a mes.- sage surcharge upon the meter at the callingstation, in addition to the usual time use charge, and particularlyin a "telechronometertype of system in which the service is metered by periodic reversals of current although it is, tov be understood that the invention in its broader aspects may be embodied in other forms for use elsewhere as suitable or desired.

It is also an object of the invention to provide message surcharge metering means which is operative to register the surcharge per message only when the calls are completed, and messa e surcharge metering means of the class set forth which is of simple character and adaptable to previously provided equipment with minimum a1- teration of existing circuits and regardless of whether a manually operated exchange or automatic or auto-manual operation is employed.

Further objects and advantages of the invention will appear from the following detailed description taken in connection with the. accompanying drawing, in which:

Figure 1 is a diagrammatic illustration of a telephone system embodying the present invention; and I Figure 2 is a fragmentary portion of the diagrammatic illustration of Figure 1, showin a substitute wiring arrangement. 9

Referring to the drawing, the telechronometer system in which I have shown an illustrative embodiment of the present invention is illustrative and may be varied within the scope of the present invention.

The system shown more or less diagrammatically in Figure 1 may be similar to the systems more fully illustrated and described in my prior Patents Nos. 1,138,174, patented May-'4, 1915,

1,138,175, patented May 4, 1915, 1,186,464, patented June 6, 1916, 1,189,525, patented July 4, 1916, 1,230,835, patented June 26, 1917', 1,547,489, patented July 28, 1925, 1,594,587, patented August 3, 1926, or it may be a, system having a zone system of rates as more fully illustrated and described in my prior Patent No. 1,694,934, patented December 11, 1928, or oi any other suitableor preferred form.

For purposes. of illustratiomsuffice it to state that the system shown more or less diagrammatically in Figure 1 comprises a calling sub-station A, called sub-station B, and connecting eord ci-fcuit C located preferably at a central switch board. V p

The calling substation A comprises a transmit-'- ter I, induction coil 2, automatic switch.hook- 3', receiver 4, and a suitable call hell (not shown). In addition, there is a telechronometer or reg ister' or meter 6 having its coils connected serially in the two limbs of the subscribers line. The sub-station A may be connected by suitable line wires 9 and ID to line signalling and switching.

apparatus in the manner more fully illustrated and described in my above mentioned prior patents, or in any other suitable or preferred manner.

The sub-stationB of the called subscriber in the particular system shown in the drawing is provided with similar apparatus the parts of which are designated by: primed reference nu merals corresponding with those of the calling line.

Current may be supplied to the talking strands of the cord circuit upon the ringing end, for example, through a supervisory relay (not shown). directly, so as to provide unidirectional flowof current over the called line, and current is supplied to the answering end of the cord circuit through a time controlled current flow reversingdevice indicated generally by the reference char acter l5 for securing periodic reversals of current flow over the calling line foroperating the telechronometer or register or meter 6' atthe. sub.- station of the calling party. A complete cycle of change of polarity occurring in the calling line from positive to negative, or vice versa, causes, an actuation or registration upon the meter 6 atv the calling station.

The time-controlled'current flow reversing olevice or pole changer l5 shown in Figure 1 de pends for'its current reversing properties upon four carbon pile rheostats l6, l1, l8, and I9 are ranged, for example, as the four arms of a Wheatstone bridge. In the diagrammatic showing, the compressed rheostatsl'fi' and I! are indicated by cross lines; and the. released rheostats. l8 and I9 are indicated by longitudinal lines. The circuit is completely broken when all of the rheostats are released. The pair of rheostats l6 and I1 and the other pair of rheostats l8 and 19 are alternately compressed, for example, by time con trolled pressure means as more fully illustrated and described in my 'prior patents, or in any other suitable or preferred manner. Means may be provided's'uch as shown and described: in my prior" Patent No. 1,694,934, for automatically changing the rate of reversals of polarity so that, for example, during the peak or busy load periodsreversals of current on the calling line may occur more frequently than during the remainder of the twenty-four hours. Also, as already pointed out, means may be provided for metering or charging at difierent rates in dinerent zones or parts of the system and for changing the rates in different zones as illustrated and 7 described in my last mentioned prior patent.

The exchange battery 25 may be connected across the bridge circuit as shown in the drawing, the negative side of the battery being shown as connected to the bridge circuit between the rheo-.

stats I! and I8, and the positive side of the bat tery being shown as connected to the bridge'cir cuit between the rheostats l6 and I9. The illustrated form of message surcharge means embodying the present invention com-' prises a slow acting relay R (preferably less than.

ten cycles per second as the telechronometer is designed not to respond-to current 'of'higher frequency to avoid operation by ringing frequen-;' cie's). provided With a circuit maker and breaker mean D,;cntrolled as toyduration of function as suchpfor example, by an adjustable cam E and thermostatically operated contact arm The reference letter H designates a messag control relay which is actuated'uponthe response of .the called? subscriber, whereby the surcharge per message occurs only when the calls are completed. The circuit maker and-breaker mean Dcomprisesa'plurality of contact erms 30, 3|, and; 32

and an-armature'34. Th contact arms 30, 36,

and 32 and armature 34 are actuated to retracted; positionand held in retractedposition, for ex- 30,3! and 32..return to thepositions shown in Figure 1.: a V The core; of the relay R has an energizing coil 45 surroundingsame- One end of this coil 451is connected through a conductor to the bridge circuit between the rheostats l1 and ill. The

" other end of. the 00117745 is connected in circuit with'a contact arm "48 the positionof which may be adjusted by the "adjustable cam E to control the duration of energization of the relay R and therebythe duration of function of the circuit maker and breakenmeans. Retardation 50 may 1 be provided between the end'of the core of the relay Randthecontact arm 48. v

The thermostaticallyoperated contact F is shown as comprising a bimetallic arm an- 'chored or fixed at one end at 52. The other end 1 of this-bimetallic arm F has a contact ,53 for contactwith the contact. arm 4;; to complete the electric circuit through the coil 45 for energizing l the relay-R; The bimetallic arm F has a pair of heating coils' 54 and55 shown as coiled aboutthe arm I, although this, of course, may var: as may the otheridetailslshown and described.

Thetrnessage' 'chargecontrol relay His shown a r as comprising a core 58. surrounded by a pair of,

energizing coils 60. and 62; Oneend of the goil; 60 is conniected'ilthrough a conductor 63;with

the bridge circuit between the rheostats l6 and I9. The other end of the coilfiil is connected through a conductor 64 with one end of the coil 54 for heating the bimetallic arm F. The other end of the heating coil 54 is connected through a conductor 65 and relay or coil 53 to the talking strand 43 at the answering end. One end of the coil 62 is connected through a conductor 68 with the bridge circuit between the rheostats l1 and 1d of the through a conductor 11!) with. one? second coil 55 for heating the bimetallic arm F; V v i The other end of the heating coil 55 is connected 'through a conductor 12 and relay or coil 13 to the, 7 other talking strand 2 at the answering end.

' A contact arm '55 has an armatur it and a contact 18fwhich contact 88, upon energization of the relay H, is adapted to be attracted into con- 20' arm 80 is connected through a conductor BI with the bridge circuit between .the -rheostats;Land

tact arms 30 and 32th the bridgecircuit betweeni' therheostats I1 and 119.. Alconductortt con nects the contact arm 3'lcto the 'bridgeirciml tbr tween the-rheostats.|15..;and-:i8;i

bodiment OfJthG, inventioni-is"asfo1lows: s

' Assuming that the ca'llingsubscriber A iraises his receiver from the switch hook 53-.ancl desires. to call through central the subscriber ,B, iclosing the hook Iswitch Lplaces current of; normalepogtene, tial upon the line wiresv9' and jii8;energizing;the;

line relay and'line signal. (not shown), whereupon, the operator makesi aconnectioncwiththe usual. 7

answering plug with the line of-the callingsubcriber through the .usualansweringgjack, thereby;

efiacing the callingsignal,;disconnectingtheline conductors 9 and iii fromiithe ,batteryigrand applying the potential prevailingjni-the :Sti'hhds 42 and 4310f the cord circuit emplo e -1 .1:

The normal current moves the magnet of; the, telechronometer 6 about its piVQtin onedirection. A reversalof current, causesth magnet about its pivot in the opposite compl ing t c e, or:.opsrat f s ssa r make, registration on the telechronqmeter ,With,.-the circuitmar andhrea i. tioned as shown in FigureY L;currentjlcws r W the positive side of the battery '25 throughcompressed rheostat 16, conductor fit contact arm 3 I, conductor 38, and relay-oreeilfiil; to the talkn s d 2,; ands r the talkie j' through conductor. 3. relay o ;cpil ti 1 V arm 3 2, conductorififigand;compressed rhe U to the negative side of thebatgtery' 25 The message charge -control relay -Hfis atedu qn-th .rr ncnsccfiths so. that the i ebareelie re he telechro om t r 'oiih 1 I a y; curs only when the .984 jis 9 l pl i' d. .Wh l call is completed, current flows from-the pos side of the battery 25 through the cond'ucto coil mpwduc m .ihheei n 0011' 5V5 5 ;and r lay. 9 s il t and. iron. thetalti il lfirc ndi st rsli e l8. s Theother end of .thecoiL, ii2- is connecteda tact witha contact arm 81!. This latter contact Briefly, the .operationzof -theg'illustrated em asaaore I0, coil 62, and conductor 68 to the negative side or the battery 25.

The flow of current through the coils 60" and 62 energizes the relay H, drawing the armature 16 to attracted position and closing the contact 18 into contact with the contact arm 80. Current then flows from the positive side of the battery through conductor 8|, contact arms 80- and 15, conductor 82, bimetallic arm- F, contact 53, contact arm 48, coil 45, and conductor 45 to the negative side of the battery 25. The flow of current through the coil 45 energizes the slowacting relay R, drawing the armature 34 to attracted position with an accompanying movement of contact arms 3| and 32 out of contactwith contacts 36 and 31, and movement of contact arms and 3| into contact with contacts 36- and 31, respectively.

This reverses the current which now flows from the positive side of battery 25 through the com pressed rheostat l6, conductor 86, contact arm 3|, conductor 39, and relay or coil M to the talking strand 43, and from the talking strand 42 through the conductor 38, relay or coil 40, contact arm 30, conductor 85, and compressed rheostat IT to the negative side of the battery 25. A message surcharge is thus recorded on the telechronometer 6 at the calling" subscribers substation in addition to the time controlled time use charge.

The flow of current through the heating coils- 54 and 55 heats the bimetallic arm F which warps in a direction to disengage the contact 53 from the contact arm 48. This opens the circuit for the coil 45, thus deenergizing the relay R, and the contact arms 30, 3| and 32 are returned by the spring 35 to the position shown in Figure 1, with contact arms 3| and 32 in contact with contacts 36 and 31, respectively. A complete cycle of change of polarity from positive to negative and back to positive, or vice versa, eitherfrom the illustrated position of the circuit maker and breaker D to the position to which it isactuated upon energization of relay R, or from the position to which it is actuated'upon energization of relay R back to its illustrated position, causes a message surcharge actuation or registration upon the meter 6 at the calling station.

The adjustable cam E isadaptedto adjustselectively as desired the position of the contact arm 48' toadjust the duration of contact of the contact 53 with the contact arm 45' upon heatingof the bimetallic arm and to adjust the interval required for the bimetallic arm F to warp the contact 53 out of contact with the arm 48. The adjustable cam E and bimetallic arm F'thus control as to duration offunction the slow acting relay R.

Terminals 90, 90 may be provided at the slow acting pole changing relay R whereby a suitable (condensers or non-inductive resistance) noise and spark suppressor means may be applied as will protect the contacts of the pole-changer spring arrangement and reduce the disturbance in the connected telephone line.

The system shown fragmentarily in Figure 2 is similar to the system shown fragmentarily in Figure 1 except for another form of wiring which is illustrative of a variation whereby the heating elements of the thermostat arm- F" may be sup-- plied from a locally controlled source, rathertha-n through the utilization of the subscriberslinecurrent as provided, for simplicity; in the diagram oi'Figure' 1.

Iii-Figure 2 the circuit from the positive side of the battery is through conductor 63 coil 60', conductor 64', and directly through relay or coil 13' to talking strand 42', the talking strand 43" being connected directly through the relay orcoil 66", conductor 65", coil 62', and conductor 58" to the negative side 01. the battery. The conductor 58'- is connected through a conductor 92 to one side of the heating coil 54', the other side of which coil is connectedthrough a conductor 93 to one side of the heating coil 55'. The other side of the coil 55' is connected through a conductor 94 to an additional contact arm 95" which has a contact 96 with which the contact arm 16' is held in contact by the spring 84'. spending with the parts-shown in Figure l are designated by primed reference numerals'corre sponding with those used in Figure 1'.

Except for the distinctions alread pointed out,

, station meter will receive a time unit charge to cover the use of equipment during the'operators, or dial, time, in ringing the line of the called party. If answered, the message chargedevice will cause a completed call or message charge"- consisting of as many telechrones, i. e., time units of telephone service, as may be required by the prevailing rate schedule. The con-- I trol of this charge is accomplished through the character of the winding or windings employed as the heating element for the thermostat arm- F; and the exact adjustment procured through the cam E.

The embodiments of the invention shown in the drawing are for illustrative purposes only, and it is to be expressly understood that said drawing and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, reference being bad to the appended claims for that purpose.

I claim:

1. In combination, a calling line having a telephone set, a called line having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, means for reversing the polarity of current over said lines and controlling the frequency of such reversals, a registering device impelled by reversals of the polarity of the line current for registering the talking intervals over the talking line, and message surcharge means for registering by reversals of current on said registering device a message surcharge in addition to the talking interval charge;

2. In combination, a calling line having a telephone set, a called line having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, time controlled means for reversing the polarity of current over said lines, a registering device impelled by reversals of talking current for registering the talk charge means for registering by reversals of current on said registering device a message surcharge in addition to the talking interval charge, and means actuated upon response of the called subscriber for causing registration of the" message surcharge only when the calls are-completed.

3'. In combination, a calling line having a tele-- phone set, a called line having a telephone set. a connecting circuit for interconnecting said' lines fortelephonic communication, means at The other parts corremunication,

the subscribers station for registering 'artalking interval charge for the-talking intervals over the 1 talking line, said registering means being actuated; by thetalking currentsource'and means operableover the connecting circuit between said lines for registering on, said registering means a message, chargein addition to the talking interval charger 4'. In combination, a calling line having a tele--v phoneset, -a called line having a telephone set,

' registering a message charge by a complete cycle of change of polarity by said pole-changer. cira connecting circuit for interconnecting said lines for telephonic communication, means actuated by the talking-current supply for, registering--21, talking interval charge for'the talking intervalsv over the talking'line, means located at'thQSUbscriberfs station and operable over the connect-;

ing circuit between said lines for registering on said registering means a message chargein addiction'to the talkinginterval charge, and means actuated upon response {of the called subscriber for causing 'registration of the message charge only when the calls are completed.

5.;In a telephone system, in combination, a callinglinehaving a-telephone set, a called line having a-telephone set, a connecting circuit for interconnecting said lines for telephonic communication, a conversational time controlled polechanger source of current supply for said system, superimposed pole-changer circuit making and breaking means for reversing the polarity of current over said lines, a relay designed tooperate slower than'ringing frequencies for operating said pole changer circuitmaking and breaking means from a first position to a second position, means actuated-upon response of the called sub-, scriber for deenergizing said relay for operation of said pole changer circuit making and break! ing means to said first position, and register means operable by the time controlled polechanger source of'current supply and by said superimposed pole-changer circuit for registering a time interval charge and a surcharge.

6.-'In a telephone system, in combination, a

calling line having a telephone set, a calledline having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, a conversational time controlled polechanger source of current supply for said sys tem,*-superim posed pole-changer circuit making and breakingmeans forreversing-the polarity of current over said lines, a relaydesigned to op,-

crate-slower than ringing frequencies for operating said pole-changer circuit making and breaking means from a first position to a second position, means actuated upon response ofthecalled subscriber for deenergizing said relay for operation of said pole-changer circuit making and breaking means to said first position, and a registering device for registering a message charge by a complete cycle of change of polarity bysaid pole-changer circuit making and breaking means, 1 said registering device also registeringa surcharge, by the reversal of current by said superimposed pole-changer circuit making and break- I ingmeans. 1 I

7.;In a telephone system, in combination, a

calling line having a telephone set, a called line having a telephone set, aconnecting circuit for interconnecting said lines for telephonic coma conversational pole-changer source of current supply for said system, superimposed pole-changer circuit making and breaking means for reversing the polarity oi current over said lines, a relay designed to opre -sl we t zan r ns g equ nci r en-Vi time-controlled 7 ating said 'pole 'chariger circuit makihgTand' breaking means from a first positionito a 'secon'd position, thermostatically .operated means actuatedupon response of the called subscriber for '5- deenergizing said relay for operation of said pole-' changer circuit making and breaking means. to:

said first position, and a-registering device; for

'cuit making and breaking means.

8.-In a telephone system, in combination, :a calling line having a telephonefseha called-line having a telephone set, ;a connecting circuit for interconnecting said lines for telephonic commue- 'nication, aconversational time-controlled -polechanger source of current supplyfor said sys tem; superimposed pole-changer circuit making breakingmeans for reversing the polarity;

of current over said lines,- a relay designedjto operate slower than ringing frequencies; for op crating said pole-changer circuit making and; breaking means from a first position to a second position, a bimetallic contact. armihaving one position forenergizing said relayior toperatiop of said pole-changer circuit making and breaking means from one position to theother position and operable when heated to, another positiont0;- deenergize said'relay-for operation ofsaid, PQle' changer circuit making and breaking means to,

its first position, and means actuated upon; i e-.

bimetallic contact arm.

sponse of the called subscriber for heating said ating said pole-changer circuit ,makingand breaking means froma first position, to a second 7 position, a bimetallic contact arm having the, position for energizing said relay tor-operation j of said pole-changer circuit making and breaking means from one position, to the other position and operable when: heatedto another posi- 3 tion to deenergizelsaid relay for operation of said pole-changer circuit making and breaking means to its first position, means actuated upon response of the called subscriber for, heating said bimetallic contact arm and means for adjusting the duration of function of said pole-changer circuit making andbreaking means.

'10.,;In a telephonesystem, in combinationfa calling lin having a telephone set, a called line;

having a telephone set, a connecting circuit for interconnecting said lines; for telephonic com-.

munication, a a conversational time-controlled pole-changer. source of current supply;for said system, superimposed pole-changer circuit maki ingand-breaking means'for reversing the polarityE of current over saidlines, a relay designed to op'-,

rate'slower than ringing frequencies for operating said pole-changer circuit making and breakpole-changer nserc i :mak nemd bre kinamea is tQ- t ing means from a first positionto asecond posir tion; a bimetallic contact arm-having one posi-e tion for energizing said relay for operation of saidcircuit -making and H breaking; means from one position to the other position and} operable when heated, to another position to de; energize said relay for operation of saidpolee,

the called subscriber for heating said bimetallic contact arm, and means for adjusting the duration of function of said pole-changer circuitmaking and breaking means, said last means comprising an adjustable cam cooperating with said bimetallic contact arm ior adjusting the position thereof.

11. In a telephone system, in combination, a calling line having a telephone set, a called line having a telephone set, a connecting circuit for interconnecting said lines for ,Ltelephonic com. munication, a conversational time-controlled pole-changer source of current supply for said system, superimposed pole-changer circuit making and breaking means for reversing the polarity of current over saidlines, a relay designed to operate slower than ringing frequencies for operating said pole-changer circuit making and breaking means from a first position to a, second position, a bimetallic contact arm having one position for energizing said relay for operation of said pole changer circuit making and breaking means from one position to the other position and operable when heated to another position to deenergize said relay for operation of said polechanger circuit making and breaking means to its first position, means for heating said bimetallic contact arm, and a message charge control relay actuated upon response of the called party for completing a circuit through said heatingmeans.

12. In a telephone system, in combination, a calling line having a telephone set, a called line having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, a conversational time-controlled pole-changer source of current supply including alternately compressed and released rheostats, a registering device actuated by line talking current and located at the subscribers line terminal, and pole-changer circuit making and breaking means connected in circuit between the system and said time-controlled pole-changed source of current supply and operable upon response of the called subscriber for causing by reversal of cur-- rent over the connecting circuit registration of a message charge when the calls are completed.

13. In a telephone system, in combination, a calling line having a telephone set, a called line having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, a conversational time-controlled polechanger source of current supply including alternately compressed and released rheostats, a registering device actuated by line talking current and located at the subscribers line terminal, polechanger circuit making and breaking means connected in circuit between the system and said time-controlled pole-changer source of current supply and operable upon response of the called subscriber for causing by reversal of current over the connecting circuit registration of a message.

charge when the calls are completed, and a relay operable when energized to operate said polechanger circuit making and breaking means to one position and, when deenergized, releasing said pole-changer circuit making and breaking means for operation to its first position.

14. In a telephone system, in combination, a calling line having a telephone set, a called line having a telephone set, a, connecting circuit for interconnecting said lines for telephonic communication, a conversational time-controlled pole-changer source of current supply including alternately compressed and released rheostats, a

registering device actuated by line talking cur.- .rentand'located at the :subscribers -line terminal, pole-changer circuit making and breaking means connected in circuit between the system and said time-controlled pole-changer source of current supply and operable upon response of the called subscriber for causing by reversal of current over the connecting circuit registration of a message charge when the calls are completed, a relay operable when energized to operate said pole-' changer circuit making and breaking means. to one :position and, when ,deenergized, releasing said pole-changer circuit making and breaking means tor operation to :its first position and a bimetallic arm controlling the circuit through said relay.

=15; in a "telephone system, in combination, a calling :line having a telephone set, a called :line having %a telephone set, a connecting circuit for interconnecting said lines for telephonic com-- munication, a conversational time-controlled pole-changer source of current supply including alternately compressed and released rheostats, a registering device actuated by line talking current and located at the subscribers line terminal, pole-changer circuit making and breaking means connected in circuit between the system and said time-controlled pole-changer source of current supply and operable upon response of the called subscriber for causing by reversal of current over the connecting circuit registration of a message charge when the calls are completed, a relay operable when energized to operate said polechanger circuit making and breaking means to one position and, when deenergized, releasing said pole-changer circuit making and breaking means for operation to its first position, a bimetallic arm controlling the circuit through said relay, and a second relay operable upon response of the called subscriber to cause actuation of said bimetallic arm to position for opening the circuit through said first relay.

16. In a telephone system, in combination, a

calling line having a telephone set, a called line.

having a telephone set, a connecting circuit for interconnecting said lines for telephonic communication, a conversational time-controlled pole-changer source of current supply for said system, superimposed pole-changer circuit making and breaking means for reversing'the polarity of current over said lines, a relay designed to operate slower than ringing frequencies for operating said pole-changer circuit making and breaking means from a first position to a second position, a bimetallic contact arm having one position for energizing said relay for operation of said'pole-changer circuit making and breaking means from one position to the other position and operable when heated to another position to deenergize said relay for operation of said polechanger circuit making and breaking means to its first position, means for heating said bimetallic contact arm, means for supplying current to said heating means from a locally controlled source of supply for actuating said bimetallic arm to deenergize said relay upon response of the called subscriber, and a message charge registering device operable by the time-controlled polechanger source of current supply and by said superimposed pole changer circuit for registering a time interval charge and a surcharge.

17. In a telephone service metering system having a calling line provided with a telephone set, a called line having a telephone set, and-a connecting circuit for interconnecting said lines for telephonic communication, the combination of a slow acting pole changer relay. provided'with adjust able cycle control, and means under theicontrol of the called line for starting the operation of said'relay and operable to stop the operation of said relay. i s g i18.- Inratelephone system, in combination, a"

calling. line having a telephone set, a called'line havingla telephone set, a connecting circuit -for interconnecting said'lines for telephonic communication, a conversational. time-controlled f pole-changer source of current supply for said system; superimposed pole-changer circuit making and breaking means for reversing the polarity of current over said lines, means for operating said, pole changer circuit'lmaking and breaking means from a first position to a second position, means for disabling said last means for operation of said pole-changer circuit making andbreaking 7 means to said first position, and a registeringdevice for registering a message charge byia complete cycle of change of polarity by said pole- V changer circuit making and breaking means.

"19. .In a telephone system, inv combination, a

calling line having a telephone set, a called line munication,

ing and breaking means for reversing the polarity of current over said lines, and register means operable by the time's-controlled pole-changer source of current supply and by said superimposed polechanger circuit for registering charge and avsurcharge.

a time interval SON sascooxi 

